Storage battery



Sept'. 3, 1935. Y J. J. DRUMM Er AL 2,013,379

STORAGE BATTERY Filed Dec. 8, 1932 INVENTORS'l A TTORNEYS.

Patented Sept. 3, i935 l I STORAGE BATTERY James Joseph Drumm, Thomas Hagyard, and Robert l-lenry Douglas Barklie, Dublin, Irish Free State, assignor to Drumm Battery Company, Limited, Dublin, Ireland Application December 8, 1932, Serial No. 646,280 In Great Britain December 9, 1931 '5 Ciaims. (Ci. 13s- 31) This invention relates to secondary or storage Example 1 batteries or electric accumulators with particular reference to those employing an alkaline electrolyte and is an improvement in or modi- .5 flcation of the invention claimed in British Specication No. 365,125.

The present invention relates particularly .to the surface for the support of the zinc plated out of the electrolyte and to special means adopted l for the preparation of this surface having any or all of the following properties:-

(1) By cathodic treatment in an aqueous caustic alkaline solution, for example caustic potash, in which zinc oxide is dissolved. the electrode or negative plate should readily and quickly receive a satisfactory smooth and adherent deposit of zinc with the minimum of local action. Such a deposition of zinc would correspond with the charging of Zinc accumulators of this type.

(2) These properties of the supporting surface for the plating out of zinc on charge of the accumulator should be retained when the accumulator is discharged to such an extent that all the zinc deposit is removed from the underlying supporting surface and the latter becomes subjected Example 2 25 to anodic treatment for long or short periods of An alloy' of iron, nickel and chromium of the time. 'I'he latter state of affairs would represent .i .i 1 k the conditions set up in a battery of such zinc type of Staybnte Anka 'the mamma s own t -m rk P rmawite cells when individual cells fall out of step with gefDrarglsred rade a s e the others and register reverse voltage on dis- Staybte 'consists of approximately 18 per 30 chlge'. t. l 1 .u t t d h cent. chromium, 8 per cent. nickel, a small percomprl; lvncge; yw rh gue eisaca centage of tungsten, and the balance iron. longitudinal sectional view of a battery plate. Anka conslsts of approxlma ely l5 per cent chromium 11 per cent. nickel, 0.15 per cent. car- According to the present invention the eleci u f trode or negative plate of the secondary battery bon and the balance iron, while Permawlte con 3o or accumulator consists basicau of nickel or sists of approximately .l5 to 20 per cent. chromicobalt alloyed with iron, the aliy being used um' 7 to lo per cept' mckel md the balance umg alone or if desired being suitably alloyed with All these material? are satlsfactory to a mg 40v any one or more of the following metalszdegree but so .far.lt has been found thi the chromium molybdenum tungsten magnesium optimum material is an alloy closely similar to 40 zinc cadmium, silver, ,manganese vanadium: Du1.1ray' This .auoy in a typlcal example' tantalum. The alloying may be accomplished by conslsts of 34% mcke-1 3'7% cm0m1wnand ap' the usual methods involving melting, casting. etc., proxlmaly 61 62% non' It 1s essental how' before the fabrication of the electrodes or by ever, that the carbon content must not exceed 45 methods based on the process ofheating, pref- 01% and the silicon must not exceed 0.2%. erably4 in a reducing atmosphere, the material on Manganese as al? lmpurftX 1S permlsslble up to which a deposit of the desired metal or metals 1% and COPP-e1 15 permlsslble jip to 05%' and i has been obtained by .methods of oloctrodepositraces of any of the other alloying metals heretion, hof, dipping, spraying1 contact-I With metallic inbefore referred 'to may have no harmful effects.

vapours, or by a, process of heating in contact In the preparation of this particular ferrowith substances containing the metal, Any 0f nichrome it has been found that the material these methods may be followed, when desirable, Works best in the fOrm 0f Wire. A Wire 0f 17 by a treatment at a raised temperature in a gauge may be prepared as followsz-the ordireducing atmosphere. nary ingots from manufacture are drawn down A suitable ecctrode material consists of nickel alloyed with iron as in the material known under the registered trade-mark Invar or Platinite, which contain respectively about 38% and 5 46% of nickel. Thus Invar contains 38 per cent. nickel and 62 per cent. iron, while Platinite containes 46 per cent. nickel, 0.15 per cent. carbon and the balance iron. The electrode or negative plate may consist of gauze, corrugated sheet, wire or expanded metal as mentioned in the parent specification. In preparing the negative electrode of the above materials, the metal surface, where necessary, should be descaed by properly pickling oi' dipping in acids. It will be found that the results obtained with the above materials vary somewhat, other things being equal, according to' whether the material has been work hardened or annealed by heating in a reducing i atmosphere.` Whether the material is used in the 20 form of gauze or wire it is preferableI to slightly work harden the wire before using in the actual accumulator.

to gauge ifi. When annealing is necessary this can becarried out by heating the material ,in air and subsequently removing the scale by pickling in acid. After about 15 gauge the material is packed together and, close annealed for several hours at temperatures varying between 600 and 900 C. After this treatment the wire is again descaled by pickling in acid so as to remove completely oxide from the surface and is drawn finally through smooth dies to the required 17 gauge. Atrthis gauge the alloy or wire is pickled at 20 C. in a mixture of 2 parts sulphuric acid to 1 part nitric acid for about 5 to 10 minutes. It is then rinsed in running water, boiled in caustic potash and kept preserved dry until required.

It should be again emphasized that any material, to prove satisfactory in the new accumulator as a supporting surface for zinc deposition, must possess both the properties outlined above. Whilst any of the materials described under Example 1 or 2 are satisfactory, the material consisting of 34% nickel, 3.7% chromium and (i1-62% iron, has proved itself the most satisfactory.

Such materials may be used in the form of wire,l wire gauze, tape gauze, tape, plain, corrugated or expanded sheet. with or without perforations, with or without a backing or core of another metal.

For example, a suitable alloy having a high -electrical resistance `is used in the form of two thin sheets, plane or otherwise, enclosing a thicker sheet of more highly conducting metal, for example iron known under the registered trademark Armco, being attached to the thicker sheet at a number ofplaces by any suitable means such as welding, riveting, etc.

When rolling sheet or drawing wire, or otherwise working metal, especially of the type o! Dullray, annealing at elevated temperatures should preferably be carried out in a non-oxidizing atmosphere or alternatively the periods of annealing in an oxidizing atmosphere should be made as short as possible, as prolonged annealsisting of metal from the group containing nickel and cobalt with 61% to 62% iron.

2. An alkaline storage battery as claimed in claim 1 wherein the alloy in addition comprises as constituent at least one of the following:-

' chromium, molybdenum, tungsten, magnesium,

zinc, cadmium. silver, manganese, vanadium, tantalum.

3. An alkaline storage battery in which the active negative material consists of zinc plated out of the electrolyte onto a supporting platehaving a smooth, clean surface oi' a nickel-iron alloy comprising 38% nickel and the balance iron.

4. An alkaline storage battery in which the active negative material consists of zinc plated out of the electrolyte onto a. supporting plate having a smooth, clean surface of an alloy comprising 34% nickel and approximately 6l62% iron with, in addition, about 3.7 per cent. chromium.

5. An alkaline storage battery in which the active negative material consists o1' zinc plated out of the electrolyte onto a supporting plate having a Ismooth, clean surface of a nickel-iron alloy comprising 46 per cent. nickel and the balance iron.

JAMES JOSEPH DRUMM. THOMAS HAGYARD. ROBERT HENRY DOUGLAS BARKLIE. 

